CVE-2020-3566: Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability
Actively exploited. At least one CVE in this advisory is listed in the CISA Known Exploited Vulnerabilities catalog — exploitation has been observed in the wild. Treat remediation as urgent.
Cisco IOS XR Distance Vector Multicast Routing Protocol (DVMRP) incorrectly handles Internet Group Management Protocol (IGMP) packets. Exploitation could allow an unauthenticated, remote attacker to immediately crash the IGMP process or make it consume available memory and eventually crash.
CSIRTS triage
- What
- Cisco IOS XR Distance Vector Multicast Routing Protocol (DVMRP) incorrectly handles Internet Group Management Protocol (IGMP) packets, potentially leading to crashes.
- Who is affected
- Users of Cisco IOS XR Software are affected by this vulnerability.
- Urgency
- Remediation is urgent due to the critical nature of the vulnerability and its exploitation status.
- Action
- Users should update to the latest version of IOS XR Software.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2020-3566
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation confirmedCVE-2020-3566Already exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 88% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2020-3566 | coverage & exploitation status | NVD · CVE.org |
Recent advisories for Cisco IOS XR
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- criticalexploitedCVE-2016-6415: Cisco IOS, IOS XR, and IOS XE IKEv1 Information Disclosure Vulnerabilitycisa-kev · 2023-05-19
- criticalexploitedCVE-2022-20821: Cisco IOS XR Open Port Vulnerabilitycisa-kev · 2022-05-23
- criticalexploitedCVE-2009-2055: Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerabilitycisa-kev · 2022-03-25
- criticalexploitedCVE-2010-3035: Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerabilitycisa-kev · 2022-03-25
- criticalexploitedCVE-2018-0167: Cisco IOS, XR, and XE Software Buffer Overflow Vulnerabilitycisa-kev · 2022-03-03
- criticalexploitedCVE-2018-0175: Cisco IOS, XR, and XE Software Buffer Overflow Vulnerabilitycisa-kev · 2022-03-03
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